Shackleton, Abraham (1696–1771), schoolmaster, was born in 1696 at Shackleton House, Bingley, Yorkshire, youngest of six children born to Abraham Shackleton and his wife Sarah Briggs, quakers. His mother died when he was six, his father when he was eight. Abraham suffered from a frail constitution which made him unfit for manual labour, so he learned Latin at the relatively late age of 20 in order to qualify as a schoolmaster. He was an assistant at David Hall's school at Skipton where he met his future wife Margaret (d. 1768), daughter of Richard Wilkinson of Knowlbank, Yorkshire, before coming to Ireland at the invitation of fellow quakers as tutor to the Coopers of Cooper's Hill and Ducketts of Duckett's Grove, Co. Carlow. On 1 March 1726 he opened a school at Ballitore, Co. Kildare, a village established by quakers in the late seventeenth century. The school was open to children of all religions. This was partly a question of economics, but liberality of outlook also played a part. Two years after its foundation, numbers had risen from 38 to 63 and continued to rise each year, attracting students from England, Scotland, Jamaica, Norway, and France, as Ballitore gained renown.
Most of the boys were destined for a career in trade or commerce and the curriculum was conventional, the staple subject being Latin, but with fees of £24 a year and two guineas (£2 2s.) entrance, only the better-off could attend. Famous pupils included Edmund Burke (qv) who entered 26 May 1741, aged 11, along with his two brothers, and stayed until April 1744. Shackleton always singled him out as one of his most able pupils, and Burke claimed in parliament, after the Gordon riots of 1780, that Shackleton had been his most influential teacher; although his significance was more moral than ideological, as by the 1790s Burke was pro-war and the age's foremost apologist for the aristocracy – a marked contrast to quaker principles. However, in his speech against dissent (11 May 1792) Burke exempted quakerism from his censure. Coming from a family with a Roman Catholic mother and a protestant father, he had been exposed by his education to the third religious group in Ireland, protestant dissent. A later pupil (entered 10 May 1813) who gained an insight into the sect was Paul Cullen (qv), later archbishop of Dublin. Abraham continued as master until 1756, with the poor of the area coming from miles around to receive food, medicine, and sometimes shelter from the family. In 1756 he made way for his son Richard, although he continued to live in the village and maintained an interest in his former pupils' welfare, as well as taking up farming and attending representative quaker meetings throughout Leinster and the annual general meeting in London in 1769, when he visited Burke. He died 24 June 1771.
Richard Shackleton (1726–92), born 28 July 1726, was educated at his father's school alongside Burke. The two became intimate and their correspondence is the most important source for historians wishing to know more about Burke's life as an undergraduate at TCD (1744–7). Shackleton entered TCD c.1745, an unusual move for a quaker, although he did not graduate as he had only attended to learn enough Hebrew to enable him to teach the subject at Ballitore. Once he had taken over as master he taught classics, mathematics, and commercial subjects to around 50 or 60 boarders. In 1770 he came to public notice when he accidentally published details of Burke's family and education. These derived from a private letter he had written in 1766 in response to precise questions about Burke, and in particular his religion. Unfortunately the letter was published in the London Evening Post (14, 17 Apr. 1770) and afforded the material for nearly all biographies of Burke until the publication of The Leadbeater papers (1862). Burke's anger exploded in a hasty and ill-tempered letter to Shackleton (19 April 1770) but the two were soon reconciled. Each year Shackleton visited Burke when he attended the annual meetings of Friends in London, and Burke returned the visits in 1766 and 1786.
On 31 May 1778 Shackleton again gained notoriety when he penned a letter on the subject of tithes to Sir Edward Newenham (qv), MP, who was pressing parliament for reform, although in general the quaker schoolmaster shunned publicity. He also corresponded privately with the American quaker Anthony Benezet, whose Caution and warning to Great Britain and her colonies on the calamitous state of her enslaved negroes (1766) started the anti-slavery movement in Great Britain and Ireland. Benezet would have been aware of Shackleton's connection with Burke. Shackleton's second wife, Elizabeth (1729–1804), daughter of Joshua Carleton and his wife Rachel Rooke, corresponded with the Scottish philosopher David Hume, complaining that he had unfairly described quakers as deists. In 1779 Shackleton resigned his position as headmaster. He spent his retirement in church work and died at Mountmellick 28 August 1792 after being taken ill en route to visit the quakers' provincial school there, of which he, like his father before him, was a governor. He had married first (2 February 1749) Elizabeth, daughter of Henry and Deborah Fuller. She died in spring 1754, nine days after the birth of their son Henry, who died aged 2. They had one other son, Abraham, and two daughters. He married his second wife, Elizabeth Carleton, on 17 October 1755; they had a son and three daughters, one of whom, Mary Leadbeater (qv), was a poet and author of the Annals of Ballitore (1862). Richard's son Abraham Shackleton (1752–1818) was born 8 December 1752, enrolled at Ballitore school 29 April 1756 and succeeded his father as master in 1779, the year of his marriage to Lydia Mellor (23 February). It was under Abraham's care that the school became an exclusively quaker establishment in 1789, a move that Richard had resisted when he had been asked to consider it in 1765. This resulted in a fall in numbers, particularly as Abraham advertised his refusal to teach those authorities required for entrance to TCD which he considered unsuitable for young minds (Monthly Magazine, 17 Aug. 1797). The situation deteriorated after his imprisonment within the schoolhouse during the 1798 rebellion. The house was occupied by rebels and soldiers in turn, and the village was sacked and burnt to the ground after 3,000 insurgents entered the village (24–30 May 1798). In 1801 he was also involved in a dispute among Carlow quakers on points of theology, and this made some quakers doubt his orthodoxy. In an attempt to revive its flagging numbers the school reopened to all religions, but was forced to close in November 1802 because of a shortage of pupils. However, it reopened in the same year to day scholars. No pupils seem to have been enrolled from 1804 to 1806 and Shackleton retired to the village mill, where he took charge of business. He still took an interest in intellectual pursuits, for in 1815 he published The court of Apollo, with other minor poems. He remained at the mill until his death (2 August 1818). In 1806 his daughter Lydia married the quaker James White and they reopened the school as a boarding establishment. By 1807 there were 55 pupils enrolled and it remained in operation until 1836. By that date over 1,000 pupils had been educated there.